磁化率能够衡量磁珠向磁力架迁移的速度,其大小取决于铁含量和氧化铁的特性。Dynabeads磁珠的磁化率是指质量磁化率,单位可以是cgs单位/g或m^3/kg(国际单位制)。对于亚铁磁性和铁磁性物质,质量磁化率取决于磁场强度(H),这些物质的磁化强度与H不是线性关系,而是随着场强增加而趋于饱和。因此, Dynabeads磁珠的质量磁化率是在固定条件下由标准操作程序而测定的。我们产品目录中给出的质量磁化率是国际单位制。磁化率由从高斯(cgs、emu)单位向国际单位的转换,是通过“高斯系数(emu/g或cgs/g)x 4π x 10^-3”而实现的。所得单位也被称为合理化质量磁化率,与(国际单位制)无量纲磁化率单位有所区别。通常,质量磁化率可用来衡量在非均匀磁场中影响物体的力(Fz)。测定Dynabeads磁珠的质量磁化率时,首先对样本称重,然后将样本放置于已知强度的磁场中。随后,再次称重得到样本重量(F1),并与关闭磁场时样本的重量(F0)进行对比。使用下述公式计算磁化率:K x 10^–3 = [(F1-F0) x m x 0.335 x 10^6],K表示质量为m的样本的质量磁化率。最后,将磁化率转换为国际单位制。
'Regulatory CD25(+)CD4(+) T cells (Tregs) play an important role in the control of peripheral tolerance. In this study we demonstrate that human peripheral blood Tregs can be divided into two distinct populations based on the expression of CCR4. The majority ( approximately 75%) of freshly isolated Tregs express CCR4 and ... More
Dysfunctional blood and target tissue CD4+CD25high regulatory T cells in psoriasis: mechanism underlying unrestrained pathogenic effector T cell proliferation.
Authors:Sugiyama H, Gyulai R, Toichi E, Garaczi E, Shimada S, Stevens SR, McCormick TS, Cooper KD,
Journal:J Immunol
PubMed ID:15611238
The balance between regulatory and effector functions is important for maintaining efficient immune responses, while avoiding autoimmunity. The inflammatory skin disease psoriasis is sustained by the ongoing activation of pathogenic effector T cells. We found that a CD4(+) T lymphocyte subpopulation in peripheral blood, phenotypically CD25(high), CTLA-4(+), Foxp3(high) (regulatory T ... More
Regulatory T cells are expanded in blood and disease sites in patients with tuberculosis.
Authors:Guyot-Revol V, Innes JA, Hackforth S, Hinks T, Lalvani A,
Journal:Am J Respir Crit Care Med
PubMed ID:16339919
RATIONALE: T-cell responses during tuberculosis (TB) help contain Mycobacterium tuberculosis in vivo but also cause collateral damage to host tissues. Immune regulatory mechanisms may limit this immunopathology, and suppressed cellular immune responses in patients with TB suggest the presence of regulatory activity. CD4+CD25(high) regulatory T cells mediate suppressed cellular immunity ... More